@article{PastekaSantosdaCostaBarrosetal.,
  author    = {Pasteka, Richard and Santos da Costa, Joao Pedro and Barros, Nelson and Kolar, Radim and Forjan, Mathias},
  title     = {Patient-Ventilator Interaction Testing Using the Electromechanical Lung Simulator xPULMTM during V/A-C and PSV Ventilation Mode},
  series = {Applied Sciences},
  volume    = {11},
  journal   = {Applied Sciences},
  number    = {9},
  abstract  = {During mechanical ventilation, a disparity between flow, pressure and volume demands of the patient and the assistance delivered by the mechanical ventilator often occurs. This paper introduces an alternative approach of simulating and evaluating patient-ventilator interactions with high fidelity using the electromechanical lung simulator xPULM™. The xPULM™ approximates respiratory activities of a patient during alternating phases of spontaneous breathing and apnea intervals while connected to a mechanical ventilator. Focusing on different triggering events, volume assist-control (V/A-C) and pressure support ventilation (PSV) modes were chosen to test patient-ventilator interactions. In V/A-C mode, a double-triggering was detected every third breathing cycle, leading to an asynchrony index of 16.67\%, which is classified as severe. This asynchrony causes a significant increase of peak inspiratory pressure (7.96 ± 6.38 vs. 11.09 ± 0.49 cmH2O, p < 0.01)) and peak expiratory flow (-25.57 ± 8.93 vs. 32.90 ± 0.54 L/min, p < 0.01) when compared to synchronous phases of the breathing simulation. Additionally, events of premature cycling were observed during PSV mode. In this mode, the peak delivered volume during simulated spontaneous breathing phases increased significantly (917.09 ± 45.74 vs. 468.40 ± 31.79 mL, p < 0.01) compared to apnea phases. Various dynamic clinical situations can be approximated using this approach and thereby could help to identify undesired patient-ventilation interactions in the future. Rapidly manufactured ventilator systems could also be tested using this approach. View Full-Text},
  subject      = {Breathing Simulation},
  language  = {en}
}
@article{PastekaSchoellbauerSantosdaCostaetal.,
  author    = {Pasteka, Richard and Sch{\"o}llbauer, Lara Alina and Santos da Costa, Joao Pedro and Kolar, Radim and Forjan, Mathias},
  title     = {Experimental Evaluation of Dry Powder Inhalers During In- and Exhalation Using a Model of the Human Respiratory System (xPULM™)},
  series = {Pharmaceutics},
  volume    = {2022},
  journal   = {Pharmaceutics},
  number    = {14/3},
  pages     = {15},
  abstract  = {Dry powder inhalers are used by a large number of patients worldwide to treat respiratory diseases. The objective of this work is to experimentally investigate changes in aerosol particle diameter and particle number concentration of pharmaceutical aerosols generated by four dry powder inhalers under realistic inhalation and exhalation conditions. To simulate patients undergoing inhalation therapy, the active respiratory system model (xPULM™) was used. A mechanical upper airway model was developed, manufactured, and introduced as a part of the xPULM™ to represent the human upper respiratory tract with high fidelity. Integration of optical aerosol spectrometry technique into the setup allowed for evaluation of pharmaceutical aerosols. The results show that there is a significant difference (p < 0.05) in mean particle diameter between inhaled and exhaled particles with the majority of the particles depositing in the lung, while particles with the size of (>0.5 μm) are least influenced by deposition mechanisms. The fraction of exhaled particles ranges from 2.13\% (HandiHaler®) over 2.94\% (BreezHaler®), and 6.22\% (Turbohaler®) to 10.24\% (Ellipta®). These values are comparable to previously published studies. Furthermore, the mechanical upper airway model increases the resistance of the overall system and acts as a filter for larger particles (>3 μm). In conclusion, the xPULM™ active respiratory system model is a viable option for studying interactions of pharmaceutical aerosols and the respiratory tract regarding applicable deposition mechanisms. The model strives to support the reduction of animal experimentation in aerosol research and provides an alternative to experiments with human subjects.},
  subject      = {Biomedical Engineering},
  language  = {en}
}